In collecting a blood sample from an artery or vein of a patient, it is necessary to treat the hypodermic syringe with an anticoagulant, such as in U.S. Pat. No. 4,057,052. The conventional way of treating such a syringe is shown in FIG. 1 where the neck of a glass vial containing an anticoagulant is broken off and an interior of the syringe treated with anticoagulant. Such glass vials have the disadvantage of dulling the puncturing tip of the needle when it touches the bottom of the vial and exhibiting sharp edges of the vial neck which can cut an operator.
In the past, it has been proposed to package a particular injectable medicine and syringe together as a unit. This was often used in "wet-dry" mixtures in which a liquid component and powder component were separated until immediately prior to use when they were mixed. Because such combined syringe and injectable medicine container were coupled as a unit, there was no possibility of interchanging needle sizes, etc. with a particular coupled unit. Such needles were formed as an integral part of the syringe itself, as shown in U.S. Pat. Nos. 2,666,434; 2,772,677; 3,397,694; and 3,630,199.
It has also been proposed to package a needle with a dry powder in its hub for mixing with liquid in a hypodermic syringe for reconstituting a freeze dried drug, as in U.S. Pat. No. 3,696,579. However, since the needle hub was of very limited capacity, it could not be conveniently used to contain sufficient liquid anticoagulant for treating an inner surface of a syringe prior to collecting a blood sample. Instead, the purpose of this patent was to inject a reconstituted drug, and not to collect and store a blood sample.
Along this same line of preparing for injecting a patient, U.S. Pat. No. 3,563,240 describes a needle adapter of a syringe used to puncture the membrane of an elongated vial like device containing penicillin, which is then injected through a nozzle of the elongated vial along with the given dose of a supplemental medication from the syringe. There is no mention in the patent of a device to treat the syringe barrel with a liquid, such as an anticoagulant, immediately prior to collecting a blood sample.
U.S. Pat. No. 3,876,771 describes a flexible syringe with a needle protector containing a liquid which is poured over a patient's skin to disinfect it prior to injection. There is no indication that the needle is or can be sold separately from the collapsible syringe.
One other U.S. Pat. No. 3,905,366, has a double ended needle with a protector having what appears to be certain internal hash marks, but there is no indication as to what these are or whether the protector contains a liquid and if so, what the liquid is for. These hash marks could well be shading for the internal surface of an empty protector. In any event, they fail to teach a device which can be sold separately from a hypodermic syringe and be used to internally treat such syringe with a liquid, such as an anticoagulant, immediately prior to collecting a blood sample.